-- a special report from -- -- Deputy national security advisor Tony Bullington is answers a reporter's questions -- let's listen. Exactly. There's 100% certainty that this happened. So here's -- important understand the intelligence community has different levels of confidence that it expresses in any given assessment. Low medium and high highs as high as they can go. They will not tell -- tell you with a 100% guarantee that anything. Has happened in terms of the assessment that they make they put together the facts. And we have certitude in the facts and you put those facts together and you make an assessment and and you evaluate that -- -- -- And -- -- is high confidence that is. Well beyond beyond a reasonable doubt which is -- standard that I think many Americans familiar with and that is the standard that we can use. This decision go all the way up to a -- himself. Asad we believe. And we have. The intelligence and evidence to back this up. Is in control. The chemical weapons. Program. And would have. We put it this way. Any standing orders to use these weapons would have been issued by side and our colleagues in the intelligence community showed in great detail. The different individuals in the chain of command who are engaged in the activities of August when he first. Cents a. He said. -- be repercussions. If there's. Be -- threatening. Secondly today. Series and the Russians -- -- concept of international supervision. Or maintenance so. Of weapons stockpiles Syria do you have a reaction to that -- -- that something. First came from. And lastly you have the reconstruction lost ground in the senate there -- more senate Democrats say they don't want to support this. -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Take every possible precaution to make sure that we can prevent and defend against anything that might arise from the use of military action. And we've we've done that we'll continue to do that. And it is our. Judgment that. President Assad in Syria would have very little interest to pick a fight the United States rumor. So I don't think that is likely at all. Second with regard to the -- Reports today. About this -- Russian initiative we have we've seen the reports. We wanna take a hard look the proposal will obviously discuss the idea with the Russians. And of course we would welcome a decision and action. By Syria to give up its chemical weapons the whole point. What we're doing is to stop Syria from using these weapons again but I think it's important -- few things in mind first of all the international community. Has tried for twenty years. To get serious sign on to the chemical weapons convention to 189. Other countries in doing so now it is one of only five countries that haven't done it and just last week. The president -- -- wouldn't even say. Whether he had chemical weapons despite overwhelming evidence he's actually use them. Well exactly. And of course we also try to work with the Russians at the United Nations. Repeatedly on Syria and chemical weapons for months. And until now. They have blocked all of our initiatives including simple press statements nevermind the Security Council resolution so that's the background. It's also important to note that Syria has one of the largest stockpiles of chemical weapons in the world spread across the country. It would certainly take time resources. And probably -- peaceful environment to deal with us. All of that said we're gonna take a hard look at this we'll talk to the Russians about it but I think it's finally it's very important to note. That it's clear that this proposal. Comes in the context of the threat of US action. And the pressure that the president is exerting so it's even more important. That we don't take the pressure off and the congress give. The -- president the authority he's requested final finally terms of where we are with congress. You know my sense is this. From all these briefings. My sense is that when members of congress. Have a chance to see the intelligence. To read it. To get the briefings to ask questions they come away convinced of two things chemical weapons were used on August 21 against civilians in Syria and he aside regime as the one -- use them. Many many members have yet to get. This classified brief. And now as they're coming back today and this week they'll have the opportunity do that we have senior officials. Going out to provide the same briefing we gave last week. And I believe that when they see the evidence it is compelling. It's overwhelming. And then it comes down to a pretty basic question. Are we or are we not going to do anything about the fact. That -- -- poisoned his own people with gas including hundreds of children that's the question before the members of congress and when they have the evidence when they see the facts. I think they'll come to the right conclusions yeah. She's the views of the -- -- -- -- taking a hard look at what portions of offered does that mean that the secretary of state when he. Mention this idea in Britain earlier today that the -- -- -- -- -- Literally just heard about this is as you did. Some hours ago so we haven't had a chance to look at it yet we haven't had chance -- the Russians about it yet we. Your word secretary said that. -- -- For all of -- without delay. That that was not. That seems off until he was speaking I think he was I believe he was answering questions speaking hypothetically about what -- let's not forget that of course we would welcome. -- giving up his chemical weapons. Doing it in a verifiable manner so that we can account for them and -- and that's the that the whole purpose of what we're trying to achieve to make sure that he can't use them again that would be terrific but. Unfortunately the track record to -- As including a recent statements by -- not even acknowledging he has chemical weapons doesn't give you a lot of confidence but. That said we want to look part of what the Russians opposed to a -- business services. Ultimatum coming in this White House to -- for all -- -- -- Again we will look at what the road Russia's proposal talk to them about it and we'll see where -- there. And our Susan Rice said it. Failing to respond. Would increased instability and that reason for in that region for a lot of Americans that concern is that the opposite would take place in fact if we did respond that would create. Further instability. How can you assure Americans congress members that that's not what would take place that would be further instability. -- I think -- could be the case is very compelling that a failure to take action. Would produce all sorts of very very negative consequences in terms of the interest of countries in the region many of whom are partners and allies. And in terms of the United States first and foremost we we we know. Without some degree of certitude that failure to take action would say -- you can use these weapons again and again and again and do -- impunity and the more you have chemical weapons used. In Syria. The chances of -- spilling over to other countries and affecting them eventually affecting us goes higher and higher second. As you know. We have a real concern that countries that either have these kinds of weapons -- aspire to get them. We'll watch that and if we don't take action they'll conclude that they can seek to acquire them and indeed use them I -- impunity so all of that. Adds to the level of risk and danger and threat United States in terms of taking action. Again what we're talking about it's very important to understand this is limited. It's focused but we believe effective in terms of it's telling -- side. Don't use this again and also making it more difficult for him to do so in a very practical way it is not going to war with Syria. It is not Iraq it is not Afghanistan it's not boots on the ground. And so I think the chances. The action we -- to take leading to greater instability are very very very small to the contrary. Failure to act. Offers the real prospect of greater instability that Americans -- after the first few days of strikes is limited targeted -- -- strikes what happens today for. Five and six what is the plan. Could be created as a result so you'll understand I can't get into the -- the details of the plan we've had an opportunity. Two get into this with members of congress classified setting ultimately they have to make a judgment there the people's representatives. And it's I wish we could go into more detail what everyone. But that's why you have elected representatives that's their responsibility to make that judgment as well. The discusses president and safety. The safety. So I was not in Saint Petersburg I was I was back home so I defer that -- -- -- Thank Yankee Tony thanks very much. Major issue question we've been having conversations with the Russians. For a long time and that was -- -- him -- -- national security advisor answered some questions there from reporters at the White House there. Jay Carney Press Secretary taking over -- some of the -- highlights that were brought up today was regarding the statement that -- secretary of state John Kerry had made. Over in London about the fact that perhaps a military strike could be averted if in fact the Asad regime. Did relinquish its chemical weapons we will continue monitoring that news conference that Jay kind -- Carney is holding. But I want to bring in our senior national correspondent Jim problem who is in DC watching. The latest from that in and Jim I know we commented just a short time ago about the fact is that perhaps there may be some mixed messages or there may be a bit of a scattered approach. And how the White House is trying to build a consensus particularly the fact. That there is more reaction out of this proposal coming out of Russia. I don't think it's. From what I'm looking at here I don't see this is a welcome -- the United States is like condition it likes a lot. But the United States can do -- -- can't rejected they have to listen to it that's what they're saying. They say they're open to -- that they're gonna talk to the Russians. How could they say otherwise. They say otherwise that so what if -- is willing to hand over its chemical weapons to international authorities the UN. Of course the United States would listen that proposal I don't think they believe it's a real proposal. They also said they were also careful to say in that news conference. That they would want that verified. They also were careful to say. That if indeed this happens. That. Then it wouldn't happen -- would only happened because. In the context of the president of the United States threatening to attack and that's why it's happening and that the continent congress should sure should still vote. To give the president that authority because it's working. Look look what's -- happening Syria is talking about giving up its its its chemical weapons so I think it's I think they are sending a message now that that that. And and it was also explained that Senator John Kerry was not making this -- proposal wasn't his proposal that Syria do this. He was answering a question and if Syria did drop. Or did in fact. Stern its chemical weapons over to the UN what -- the United States do any of course said he'd welcome that -- That was sort of grabbed on to by Russia who propose this happen. And Syria which who -- who then said okay it will will listen -- that will do that. To protect our people let's let's start talking about that well. That's a good tactic for Syria that delays things and delays any -- any strike and also makes people have second thoughts about allowing the United States to strike right away. So I think accounting gums up the works a little bit here the united he's gonna have to listen and extricate itself from this. Or. Force Syria to do it how much. I think maybe people who watch in the Middle East and -- covering the Middle East since the eighties in Lebanon. People who watched the Middle East for a long time. Find hard to believe. That Syria would voluntarily. Give up its chemical weapons to an international authority. What they're gonna do most likely is say something like will do that if Israel gives up its nuclear weapons and of course neither those two things are willing and. Jim I want to talk just for a minute about the push by the White House two to move members of congress that are either on offense or or adamantly opposed to any kind of military action. As the president has certainly been making out his case and also other representatives have been trying to get support for any kind of military strike. When members of congress here Bishara -- side respondents saying that if in fact there is any kind of action on behalf of the US military that there would be retaliation. How closely are members of the house and the senate listening. To what he is saying. Well I think it's a it's a factor. What he's saying and I think the -- administration is is listening in fact Susan Rice is just a few minutes ago here on this broadcast said. That they believe. -- the United States believes that a limited strike will not in fact. Get a response from some military response from Syria -- some kind of reaction some kind of bombing of of of Israel or attack on Israel are attacked by Hezbollah on Americans. They believe that a limited strike would not do that they realize then they believed that Syria would be Syria and certainly Hezbollah. And al-Qaeda would recognize and attack on the United States -- -- -- our soldiers who are embassies. When in fact mean more retaliation -- a -- in a bigger retaliation. So. The United States is heard that herbicide said and they responded to an already. Saying that they don't believe that's gonna happen. As far as what's being listened to on the hill I don't think that my analysis is that is not the biggest factor. Some kind of response. I think the hill and congress both sides of the aisle want to make sure that Israel is protected. They're trying to figure out what is the best way to do that is invest in fact. To respond now and let Syria know that they can't use chemical weapons and or other kinds of weapons and they can attack Syria. And that we're watching what they're doing with chemical weapons or -- them measuring that against what you mention. Will an attack. By the United States. On Syria even if it's limited mean that. Rockets are going to start heading toward. Israel. Israel has pretty good defenses. And they can and stop them. Most rockets' most missiles coming. From especially from Hezbollah other terrorist organizations. What they can do against Syria. They probably could stop those as well. All right senior national correspondent Jim -- in Washington Jim thank you for that's. Of course have a complete write up on abcnews.com. As the president will be making his. Full appeal to United States people tomorrow night and a prime time address. For now -- -- -- our New York with this ABC news digital special report. This has been a special report from me.

This transcript has been automatically generated and may not be 100% accurate.

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